Numerous key issues remain unresolved regarding psychostimulant medication, behavior modification, and combined treatments for ADHD. A primary question is whether the need for medication and the required dosage varies as a function of the presence and the intensity of concurrent behavioral treatments. Do, as their proponents argue, combined treatments enable use of lower "doses" of both medication and behavioral treatments? Our parent study examines the relative effects of and interactions between different doses of behavioral (none, low, and high) and pharmacological (pl, .15, .3, and .6 mg/kg MPH t.i.d.) treatments for ADHD children by evaluating their separate and combined effects in a controlled summer research program in a crossover, efficacy design in which each child (N=144; aged 5 to12) receives all conditions. The following specific aims are addressed in the parent grant: 1) do dose-response curves of medication change in the presence of differing intensities of behavioral treatment, and does the answer to this question vary with the dose/intensity of the behavioral treatments and medication; 2) Do the answers to question 1 depend on (a) domain of functioning, (b) setting (i.e., recreational, classroom, home) or (c) individual differences (i.e., age, gender, severity, comorbidity). Our preliminary results (1/3 of the Ss) suggest that total daily dose of medication can be reduced from an average of 60 mg MPH per day to 10 to 20 mg MPH per day, depending on the concurrent behavioral treatment, and the need for medication in the home setting is eliminated for many children if adequate behavioral parent training is provided. Given recent societal concerns about medication use in children and concerns about long-term side effects, these findings may have great public health importance. The current application seeks to extend the results from an efficacy study to an effectiveness study. Children will begin the school year assigned to no, low, or high behavior modification conditions. Children's functioning will be assessed weekly, and medication will be added to their treatment regimen when functioning deteriorates to a predefined level. Outcome measures include survival to medication use, Generalizability of dose-response from the STP to the school setting, ending doses after maintenance treatment, and the effects of individual differences. [unreadable] [unreadable]